Investigating the interface between plant metabolism and development

我的研究项目使用分子遗传学和生化工具来研究与腺嘌呤和腺苷代谢相关的酶活性，以确定它们对植物发育的贡献。这些酶被认为是“管家”活动，因为它们在所有细胞中以不同程度表达，满足基本的代谢需要；它们通常参与多种生化途径。相应基因的突变导致复杂的表型，通常涉及不育或致命，当基因被敲除时，这给分析带来了挑战。我们通过研究具有不同残余酶活性的突变体来解剖这些表型。这使我们能够确定每种酶活性影响的植物代谢临界点以及依赖该功能的植物发育组成部分。我们的研究表明，这些酶发挥着令人惊讶的动态作用，影响发育的关键方面和影响各种亚细胞区室：一个是介导整个植物细胞中转甲基化反应所必需的关键蛋白质-蛋白质相互作用的“枢纽”，另一个控制蛋氨酸循环中产生的关键代谢物的丰度。这种代谢物含量的变化对植物的肥力和发育有重要影响。对特定酶活性靶向降低的突变体和基因沉默系的研究揭示了这些基本生化途径和植物激素信号之间的迷人的串扰，其结果是关键发育事件的基础。我在这项研究中使用拟南芥，因为它易于维护，基因操作和分析。由于本研究的靶点存在于所有植物中，因此研究结果具有广泛的相关性。目前的研究具有提高非生物胁迫耐受性、维管发育和作物生产力的潜力。

My research program uses molecular genetic and biochemical tools to study enzyme activities associated with adenine and adenosine metabolism in order to identify their contributions to plant development. These enzymes are considered "housekeeping" activities as they are expressed in all cells to varying extents where they fulfill basic metabolic needs; they often contribute to multiple biochemical pathways. Mutations in the corresponding genes result in complex phenotypes that often involve sterility, or lethal, when knocked-out making them a challenge to analyze. We dissect these phenotypes by studying mutants that have differing residual enzyme activities. This allows us to determine the critical points in plant metabolism that each enzyme activity affects and the components of plant development that rely that function. Our research shows that these enzymes fulfill surprisingly dynamic roles impacting key aspects of development and affecting various subcellular compartments: one is a "hub" mediating critical protein-protein interactions essential for transmethylation reactions throughout plant cells, and another controls the abundance of a key metabolite produced in methionine recycling. Changes in the content of this metabolite have critical effects on plant fertility and development. The study of mutants and gene silencing lines with targeted reductions in specific enzyme activities reveals a fascinating crosstalk between these basic biochemical pathways and plant hormone signaling, the results of which underlie key developmental events. I use Arabidopsis thaliana for this research because it is easy to maintain, genetically manipulate and analyze. Because the targets of this research are present in all plants, the results have broad relevance. The current research has the potential to improve abiotic stress tolerance, vascular development and thus crop productivity.